Is Marco Rubio “the electable conservatve”?

Nate Silver considers whether Marco Rubio is the most electable conservative in the putative field. His answer appears to be “yes, but.”

[L]ong before Republican voters in Iowa and New Hampshire cast their ballots, the potential nominees will be competing against one another in the so-called “invisible primary.” In this stage, which is already under way, they hope to persuade party insiders that they represent the best path forward for Republicans in 2016. The more successful they are at doing so, the more they will be rewarded with money, endorsements and the talent to run their campaigns, giving them a huge advantage once voting actually does begin three years from now.

Mr. Rubio’s most persuasive pitch to Republican Party insiders may well be that he is more popular than other, ideologically similar candidates. Some of those candidates, like Mr. Ryan, can probably offer a richer intellectual defense of conservatism, or can claim to have been better vetted. Several others, like Gov. Bobby Jindal of Louisiana, have more executive experience. Mr. Rubio’s relatively favorable public image represents his comparative advantage. (There are also the facts that Mr. Rubio is Hispanic and is from Florida, but these advantages boil down to electability as well: the possibility that he might help Republicans make gains with Latinos, and that he could give them a lift in an especially important swing state.)

What makes matters tricky for Mr. Rubio is that, at the same time he is hoping to persuade Republican party insiders that he deserves their support, he will also need to maintain a reasonably good image with the broader electorate lest his electability argument be undermined. . . .When the wider electorate learns that Mr. Rubio’s positions are in fact hard to differentiate from those of other conservative Republicans, will his favorability ratings turn mediocre, as Mr. Ryan’s now are?

This is not meant as a rhetorical question. One measure of political talent, and something that characterized both Mr. Reagan and Mr. Obama, is the ability to sell ideas to voters across a wide range of the political spectrum. Perhaps Mr. Rubio will prove to be such a talent. Otherwise, if Mr. Rubio holds a fairly ordinary (and conservative) set of Republican positions, his popularity ratings may wind up being ordinary as well.

This is a good analysis, I think. However, Rubio is already in the process of differentiating himself from most conservative Republicans on the hot-button issue of immigration. This move may well make Rubio harder to nominate but easier to elect.

Silver also presents his rating of the conservatism of key Republicans past and present, based on a methodology explained in the piece. Obviously, his ratings aren’t hard science, and his cross-era comparisons seem problematic. Nonetheless, the ratings are fun and, with a few exceptions, don’t strike me as far wide of the mark.

Here is a sampling (the higher the number, the more conservative the politician is said to be):